Kirsten Williams August 24, 1999
Headquarters, Washington, DC
(Phone: 202/358-0243)
June Malone
Marshall Space Flight Center, Huntsville, AL
(Phone: 256/544-0034)
RELEASE: c99-c
NASA, THIOKOL COMPLETE $1.7 BILLION SHUTTLE MOTOR AGREEMENT
NASA and Thiokol Propulsion of Brigham City, UT, have
completed negotiations for a contract worth up to $1.73 billion
for 73 Space Shuttle Reusable Solid Rocket Motors. The motors --
two are used per flight -- are the primary component of the
Shuttle Solid Rocket Boosters, providing 6.6 million pounds of
thrust or 71.4 percent of what the Shuttle needs for liftoff.
"This purchase will support Shuttle launches for several more
years," said Ben Goldberg, manager of the motor project at NASA's
Marshall Space Flight Center, Huntsville, AL. "This contract
includes performance, as well as cost incentives for our industry
partner. We're seeking ways to reduce cost while maintaining the
important level of safety. Our overriding requirement in this
program continues to be safety."
The contract calls for manufacture and delivery of the new
motor components to NASA's Kennedy Space Center, FL, to begin this
fall and continue through September 2004. Thiokol also will
conduct post-flight review of the last motors flown, carrying the
contract through 2005. In addition to 35 sets of flight motors,
the contract also includes three motors that will be used in
ground testing to ensure quality and prove new materials,
manufacturing techniques and hardware suppliers.
The original solid fuel motor was redesigned in 1986. Each
motor is about 126 feet long and 12 feet in diameter and contains
1.1 million pounds of propellant. The propellant is mixed and
then cast in four hollow, cylindrical metal casings. When it
solidifies, it has the color and consistency of a pencil eraser.
A forward dome containing the igniter and an aft dome with a
steerable exhaust nozzle are attached. The motors burn for about
123 seconds before they burn out and are jettisoned to descend by
parachute into the Atlantic Ocean.
During flight, each motor puts out the equivalent of about
15.4 million horsepower. The solid fuel motor's combustion gas
temperature approaches 6,000 degrees Fahrenheit -- nearly two-
thirds the temperature of the Sun's surface. At that temperature,
steel doesn't melt; it boils. After each flight, the segmented
motors are recovered and disassembled. The cylindrical motor cases
are cleaned, reinsulated and refilled with propellant. The
exhaust nozzles are refurbished, and other components are replaced
as needed. Nose cone and aft skirt assemblies are added to turn
the motor into a completed booster.
With this new contract, NASA will have purchased 230 flight
motors and 11 flight support motors to date. The Marshall Center
manages the motor program. Thiokol, a division of Cordant
Technologies, is the prime contractor.
-end-